Fingerprint Sensor Pixel Array Layout With Overlapped Circuit Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing capacitive fingerprint sensor chips have a low pixel array proportion and a large chip area, particularly in small-area sensors, necessitating an increase in pixel array proportion and reduction in chip area.
Innovation Solution
The fingerprint array structure incorporates a circuit layer that overlaps with the pixel array, featuring a shielding layer and connecting line groups to electrically connect pixel units, with non-pixel circuits positioned below the pixel array, reducing chip area and increasing pixel array proportion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the pixel array proportion is increased, then the chip area is reduced, but the circuit layout complexity increases
Solution Approach 1:
The patent applies three-dimensional stacking technology to arrange the pixel array and circuit layer in different spatial layers. The pixel array is positioned in the first layer while circuit components are arranged in the second layer, allowing vertical integration. This dimensional transition from planar to立体布局 enables the pixel array proportion to exceed 90% while maintaining complete circuit functionality, effectively resolving the contradiction between increasing pixel proportion and managing circuit layout complexity.
Solution Approach 2:
The patent implements a nested structure where the circuit layer is positioned directly beneath the pixel array, with non-pixel circuits arranged in the second layer below the pixel array in the first layer. This nesting arrangement allows circuit components to be embedded within the vertical space occupied by the pixel array, maximizing space utilization and enabling high pixel array proportion without compromising circuit functionality.
2Area of stationary object
If non-pixel circuits are positioned below the pixel array, then the pixel array proportion increases, but the signal interference risk increases
Solution Approach 1:
The patent introduces a shielding layer as an intermediary component positioned between the pixel array in the first layer and the non-pixel circuits in the second layer. This shielding layer acts as a mediator that blocks electromagnetic signals from the circuit layer from interfering with the pixel array, while still allowing the compact vertical integration to maintain high pixel array proportion. The shielding layer effectively decouples the spatial proximity from electrical interference.
Data Source
AI summary
Disclosed in the present application is a fingerprint array structure, a fingerprint sensor chip, and an electronic device and relates to the technical field of fingerprint identification. The fingerprint array structure comprises a pixel array, a circuit layer and a plurality of connecting line groups, where the pixel array comprises a plurality of pixel groups, each pixel group comprises at least two pixel units, the circuit layer comprises a plurality of pixel circuits and a plurality of non-pixel circuits, at least one portion of a projection of the circuit layer perpendicularly facing the pixel array overlaps the pixel array, each pixel circuit is electrically connected to one pixel group through one connecting line group. According to the present application, the proportion of the pixel array of the present application is higher and the chip area is smaller on the condition that the size specifications of pixel arrays are the same.